The present invention relates to a device which is mounted in a storage battery to measure electrolyte concentration and also indicate low electrolyte level. The invention will provide a motorist or mechanic with a quick visual check of the electrical charge and will warn of low liquid level in the battery. In this way any deterioration caused by aging or a faulty charging system can be readily detected and remedied.
The invention utilizes differentially-weighted, floatable slides and an optical system through which the position of the slides can be viewed from a point outside the battery. When the battery is fully charged, all the slides float. This corresponds to maximum concentration and density of the battery's electrolyte. A caption on the slide nearest the optical system appears in a window mounted in the top surface of the battery. As the battery discharges, the density of the electrolyte decreases; the differentially-weighted slides sink in succession. The captions on these slides appear one by one in the window. When the battery is completely discharged, the last slide--which has a density slightly less than that of water--remains floating and its caption indicates the discharge state of the battery. Should the electrolyte evaporate or leak to a dangerously low level, however, all the slides will sink; this exposes a low level caption placed on a hitherto occluded wall of the slide container.
It is one objective of the present invention to indicate in words the condition of charge of a storage battery.
It is a second objective of the present invention to utilize slides which float or sink according to the condition of the electrolyte and according to its level.
It is a further objective of the present invention to provide a simple and accurate method for economically producing the slides required in the construction.
These and other objectives are met by the invention to be explained in the appended description and the drawings.